So for several months I have been chasing a high idle, erratic shift problem. I have extensively searched for the common intake gasket leak, and do not think that is my issue (but I will be changing the IM gasket this spring, just for good measure).

I believe I have isolated the problem to be the TPS, unfortunately using "Bro-Science" to do so, so I wanted to see if I am missing something here.

I replace the TPS with a BWD brand sensor about 2 months ago. (FLAPS does not stock the Delco part). This fixed the issue for a couple weeks, then it returned, and it has gotten progressively worse. As of today, the car was borderline undriveable.

Shift points were all over the place, and every time i came to an idle stop, if I put the car into neutral, the idle would be between 1500-2000 RPM. Turing the car off and back on would restore normal idle (indicating bad TPS).

So today, I swapped the original "bad" TPS back into the car. I was able to make a 5 mile test drive, and shifts were normal, and the car made several stops, and idle remained normal. I should note ... the original problem was very erratic, only happening once a day or so.

So, my "Bro-Science" diagnostic is: if it were something other than the TPS, I should have seen the same, constant issue with either TPS. Since the old "bad" TPS made the short test drive without issue, I believe the new TPS is bad ... and is worse than the old.

If all this sounds reasonable, I will order a Delco TPS, which will take a week or so to get here, and just deal with the original one until then. (At least the car is driveable with that one).

My main question is, is there anything else that would come from switching the sensors "fix" the issue, that would not be related to the sensor itself? I really don't wan't to throw another $45 sensor in there if that isn't the problem, and one thing I always have a hard time accepting is a new part, bad out of the box ... especially electrical parts which are non returnable at the FLAPS.

Bad TPS. THERE IS NO AFTERMARKET TPS that is reliable including the reboxed AC Delco part. Pick and Pull is the best place to get one that will last. Any 00-02 S-Series will work. Another place of failure is a bad connector on the TPS.

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Bad TPS. THERE IS NO AFTERMARKET TPS that is reliable including the reboxed AC Delco part. Pick and Pull is the best place to get one that will last. Any 00-02 S-Series will work. Another place of failure is a bad connector on the TPS.

Thanks Nuc. I like the idea of a $5 Pick n Pull part even better. I'll probably grab a few of them just in case.

I checked the TPS connector as good as one can visually, and all looks well. This car was a one owner, garage baby, so it has really good, clean wires and connectors. (everything under the hood literally looks and feels like new), so I'll stay focused on the TPS for now.

I've ran an aftermarket TPS in most (all?) of our family's 8 or so Saturns over the years without issues. YMMV, of course, but I never had any issues. I'm not terribly OCD about all the parts being OEM though. Just replace it again and if it works, move on with life.